16alpha-thiol corticoids and their derivatives



United States Patent 17 2,988,557 16a-THIOL CORTICOIDS AND THEIR DERIVATIVES Hans Reimann, Bloomfield, and Elliot L. Shapiro, Irvington, N.J., assignors to Schering Corporation, Bloomfield, N.J., a corporation of New Jersey No Drawing. Filed Dec. 16, 1959, Ser. No. 859,856 17 Claims. (Cl. 260-69745) This invention relates to a new series of therapeutically active synthetic steroids and to methods for their preparation. More particularly, this invention relates to certain lfia-thiol steroids of the pregnene and pregnadiene series and to derivatives thereof which display important therapeutic activity in the treatment of arthritis and other infiammatory conditions.

It is now well established that the eflicacy of early steroidal therapeutic agents such as cortisone and hydrocortisone can be enhanced substantially through modification of the structures of these hormones so as to reduce or delay inactivation of the molecule believed to be promoted by natural mechanisms within the human body. To this end, past efforts have resulted in the preparation of the A and A derivatives, C-9 halogenated and C-6,9-dihalogenated derivatives, -2 and C-6 methylated derivatives, 0-14 and C-16 hydroxylated derivatives, 0-16 methylated derivatives, and combinations of these structures. While certain of the above-enumerated compounds, and particularly the C-9 halogenated compounds, having displayed remarkably enhanced anti-inflammatory activity, at least some have also evidenced untoward side effects such as increased salt retention and edema-producing characteristics, disturbances in estrogenic and androgenic activity, loss of bone calcium, ulcerogenesis, potassium loss, etc. Of particular interest from the standpoint of present research elforts are the salt and water retention characteristics induced through the use of several of the otherwise most efiicacious anti-inflammatory agents available today including, for example, the 9ahalo corticoids.

As mentioned above, the present invention is based, in part, on our discovery that the novel compounds of the instant claims are useful anti-inflammatory agents. Moreover, the presence of the (2-16 thiol substituent in the 9a-halo compounds of this invention reduces or eliminates the undesirable salt retaining activity normally character-f istic of 9a-halo compounds without eliminating their anti-inflammatory activity.

The novel compounds of this invention may be represented by the following general formula:

and the 1(2)-dehydro analogues thereof, in which R may be H, lower alkyl, or lower alkanoyl; R may be H, a monoor dicarboxylic acid radical having up to 10 carbon atoms, the sulfate radical, or the phosphate radical; Y may be (H,fiOH) or =0; and X may be H or halogen.

In general, the novel compounds of this invention are prepared by the addition of sulfur compounds such as hydrogen sulfide, lower alkyl mercaptans (e.g. methyl and ethyl mercaptan), and lower thiol alkanoic acids (e.g. thiolacetic acid and thiolpropionic acid) to suitable 16-dehydro-20-keto steroids to give the corresponding l6a-thiol-20-keto compounds. These compounds are then subjected to further reactions well known in the art to convert them to the cortisone, hydrocortisone, prednisone and prednisolone derivatives indicated by the above formula.

While many variations in starting materials and reaction sequences are possible, the following table, Table 1, represents the more preferred sequence for preparing the compounds of this invention. For purposes of illustration only, the thioacetoxy and acetate groups are employed in this sequence, as well as in the subsequent description thereof, as the 16oc-thi01 substituent and the 21- acyl substituent, respectively. It is understood, however, that no limitation, except as defined by the appended claims, is intended. I

TABLE I 4,9(11),16-pregnatrlene-21-ol-3J0'dione ZI-acetate (I) l AeBH THF 16a-thloaeetory-4,9(l1)-pregnadlene-21-ol-3,20-dlone 21-acetate (II) Oorynebaeterlum slmnex (A'IOO 6946) 16u-thloBcetoxy-1,4,9(11 ol-3,2D-dlone 2l-acetate 'III) 16a-thtoacetoxy-20-cyano-1,4,9(11),17(20)- pregnstetraene-2l-ol-3-one ZI-acetate (V) lfia-thioacetoxy-l 4 9(11)-pregnatrlene- 17a,21-dlol-8,20-dl'one 21-acetate v1 -pregnat'rlene-2l- KON l6a-thioacet0xy-20-cyano-4,9(11)- pIg)nadlene-20,21-diol-3-one zl-acetate P0 Cla 16a-thloacet0xy-20-cyano-4,9(11),17(20)- pregnetrlene-21-ol-3-one 2l-acetate (XII) 2. KHOO:

16a-thloaeetoxy-4,9(ID-pregnadlenel7a,21-dl0l-3,20-dlone 21-acetate (XHI) NBA (H10, NBA (H 0, organic or c solvent) s0 vent) lfia-thioacetoxy-9a-bromo-1-4-pregnadiene- 116,17a,21-tri01-3,20-di0ue Zl-acetate (VII) lfia-thloacetoxyprednlsolone 21-acetate (VIII) 16athioacetoxy-sa-bromohydrocortlsone 21-ecetate (XIV) l Zn l6a-thloaeetoxyhydroeortlsone 21-acetate OrO: H28 04 E01 Acetone lGa-thioacetoxy- ISa-thioacetoxycortisone zl'acetate hydrocortlsone (XVI) (XVII) As indicated schematically above, the compounds of schematically in Table II, compound XIX may be oxidized to give l6a-thioacetoxy-9a-fiuoroprednisone ZI-acetate (XX) or hydrolyzed to give 16a-thioacetoxy-9a-fiuoroprednisolone (XXI) by methods previously described. Analogous treatment of l6m-thioacetoxy-9a-bro1nohydrocortisone 21-acetate (XIV) yields the corresponding 90- fluorocortisone and 9a-fiuorohydrocortisone derivatives.

TABLE II 16a-thloacetoxy-9u-bromo-1,4-pregnndiene-11B,17a,21-trl01-3,20-di0ne Zl-acetate (VII) lKOAc 16a-thloacet0xy-9fi,llfi-oxido-1,4-pregnadIene-17a,21-diol-3,ZO-dione ZI-acetate (VIII) 16a-thioaceboxy-h-fluoroprednlsone 21aeetate (XX) rium simplex (ATCC 6946), to the l-dehydro compound III and treated with potassium cyanide to form the 20- cyanohydrin (IV) which is dehydrated with phosphorus oxychloride in pyridine to 16a-thioacetoxy-20-cyano-1,4, 9(1l),17(20)-pregnatetraene-21-ol-3-one Zl-acetate (V). Hydroxylation at the C-17 double bond with potassium permanganate and cleavage of the resulting ZO-cyanohydrin with potassium bicarbonate completes the corticoid dihydroxy-acetone side chain and yields l6a-thioacetoxy- 1,4,9 1 l -pregnatrienel7a,2 l -diol--3,20-dione 2 l-acetate (VI). This compound is then treated with N-bromoacetamide (NBA) and Water in the presence of perchloric acid to give 16a-thioacetoxy-9u-bromo-l,4-pregnadiene-11p, 17a,21-tri0l-3,20-dione 21-acetate (VII) which is dehalogenated by treatment with zinc dust to form l6a-thioacetoxyprednisolone 2l-acetate (VIII). Oxidation of this compound with chrornjc acid-sulfuric acid mixture gives l6a-thioacetoxyprednisone 2l-acetate (IX). The 21-acetates in the above reaction sequence may be hydrolyzed to the corresponding 2l-aleohols by treatment with mild acid or base, or by means of a microorganism such as F lavobacterium dehydrogenans. Thus, compound XVIII is treated with dilute hydrochloric acid to give l6u-thioacetoxyprednisolone (X). As indicated in Table I, omission of the 1,2-dehydrogenation step leads to the preparation of the corresponding l6a-thioacetoxycortisone and 16a-thioacetoxyhydrocortisone derivatives.

Where other 9a-halogenated compounds are desired, the 9a-bromo-compound, l6a-thioacetoxy-9a-bromo-1,4-pregnadiene-ll5,l7a,2l-triol-3,20-dione Zl-acetate (VII) for example, is treated with potassium acetate to form the 95,11,8-epoxide (XVIII) which is then reacted with hydrogen fluoride to give 16a-thioacetoxy-9a-fluoro-prednisolone ZI-acetate (XIX). Hydrogen chloride or hydrogen iodide could be used in this step to produce the corresponding 9a-chloroor 9a-iododerivatives. As shown 1Ga-th1oacetoxy-Qa-fluoroprednisolono 21-acetate (XIX) H18 04 Acetone \H C1 The reaction sequences described above, using hydrogen sulfide instead of thiolacetic acid, lead to the preparation of l6a-thiol and l6a-thiol-9a-haloprednisones, predniso lones, cortisoues, and hydrocortisones. Correspondin l6a-alkylmercapto and l6a-alkylmercapto-9a-halo deri tives. are prepared analogously by employing lower alkyl mercaptans as the sulfur compounds.

Other l6-dehydro-20-keto steroids may be used as starting materials in the preparation of the novel compounds of this invention. For example, the thio compound may be added to 4,16-pregnadien-2l-ol-3,l1,20- trione Zl-acetate to give a l6a-thio-substituted-ll-dehydrocorticosterone 2l-acetate which may be converted to the 17a-hydroxy compound, IGa-IhIO-SUbSIlIUICd cortisone Zl-acetate, by treatment with cyanide followed by dehydration and hydroxylation as described above. The cortisone derivative may be microbially converted to the ldehydro compound, or it may be converted to the thio-substituted hydrocortisone by protection of the C3 and C-20 carbonyl groups, as the ethylene ketals for example, reduction with a suitable reagent such as sodium borohydride, and hydrolysis of the ketal groups with dilute acid.

As another example of starting material, the thio compound may be added to l6-pregnen-3a-ol-l1,20-dione. The addition compound is converted to the ZO-cyanohydrin as previously described and then dehydrated, hydroxylated and hydrolyzed to give the l6a-thio-substituted pregnane-3a,l7a-diol-l1,20-dione. This compound is then brominated at C-2l with bromine in a suitable solvent such as chloroform and the bromine replaced by treatment with sodium acetate. The resulting ester, 160cthio-substituted pregnane-Ba,l7a,2l-triol-l1,20-dione 21- acetate, is oxidized to the 3-ketone by chromic acid. Bromination and dehydrobromination of the 3-ketone gives loa-thio-substituted cortisone and prednisone acetates. Alternatively, the prednisone derivatives may be prepared from the saturated 3-ketone by' treatment with selenium dioxide or by microbiological dehydrogenation with organisms such as Protamino'bacter alboflavum (ATCC 8458) and Protaminobacter' rubram (ATCC 8457)'which are disclosed in U.S. Patent-No. 2,876,171 issued March 3, 1959.

In a further variation of the synthetic sequence, the starting material may be a 16-dehydro-20-keto-1l-desoxypregnane derivative such as l6-allo-pregnen-3 3-o1-20-one B-acetate. The thio compound is added to the 16-dehydro--keto system as described above, following which the 17:1- and 21-hydroxy groups are introduced as before. The resulting compound is then hydroxylated in the 11- position by a microorganism such as Curvularia'lunam (QM 120h). Acetylation at C-21 andintroduction of the 3-keto-A or 3-keto-A system as previously described gives the 16a-thio substituted hydrocortisone or prednisolone 21-acetates which may be dehydrated at C-9(11) with a reagent such as methanesulfonyl chloride in pyridine. The dehydrated product may then be converted to 9a-halo-1-thio-substituted corticoids as described above.

In the synthesis of the compounds of our invention, the l7a-hydroxy groups may also be introduced by microbiological hydroxylation with an organism such as Cephalothecium roseum (ATCC 8685). Thioacetic acid, for example, may be added to 4,16-pregnadiene-115,21-diol- 3,20-dione 21-acetate to give 16a-thioacetoxy-4-pregnene- 1l,8,21-diol-3,20-dione 21-acetate which is then incubated with C. roseum to give directly l6a-thioacetoxyhydrocortisone 21-acetate. Dehydrogenation by the use of Corynebacterium simplex (ATCC 6946) gives IGOt-thlOfiCtOXY- prednisolone 21-acetate. These compounds may be oxidized to the corresponding ll-keto steroids (i.e. the corresponding cortisone and prednisone derivatives) with an oxidizing agent such as chromic acid, or dehydrated at C9( 11) by treatment with a reagent such as methanesulfonyl chloride in pyridine and converted to the 90:- halo-lfiu-thioacetoxy corticoids by methods previously described. By the same sequence of reactions, starting with the addition of methyl mercaptan for example, the corresponding 16a-thiomethylcorticoids and l6a-t hiomethyl- 9a-halocorticoids may be prepared.

The addition of the thio compounds may be carried out in the thio compound per se as a solvent, when it is a liquid at suitable temperatures, or in an inert solvent such as methylene chloride, chloroform, dioxane, tetrahydrofuran or benzene. A catalytic amount of a strong acid, such as perchloric or p-toluenesulfonic acid, or of a base, such as piperidine, may be added. The reaction is generally carried out at temperatures between 15 C. and 100 0., although higheror lower temperatures may be used. The reaction time may vary considerably, depending upon the compound and the temperature employed, but is generally between 15 minutes and 48 hours. In general, a large excess of the thio compound is employed.

The novel compounds of this invention may be used as the 21-alcohols or as suitable esters thereof. Useful esters, for example, are the acetate, propionate, iso-valerate, enanthate, tert.-butyl acetate, and cyclopentyl propionate. Other valuable esters are the phenoxyacetate and substituted phenoxyacetates, such as the 4-chloro-', 4-bromo-, 2,4-dibromo-, 4-methyland 4-methoxy-phenoxy acetates; the furoate and substituted furoates, such as the 5-chloro-, 5-bromo-, S-methyland 5-tert.-butyl furoates; the carbethoxylate, etc.

Water soluble esters such as the monosodium succinate, phthalate, sulfobenzoate, phosphate and sulfate as well as glycinate salts, gluconates, etc. have great utility.

The esters are generally prepared from the c'orresponding 21-hydroxy steroid by treatment with a suitable acidhalide or acid anhydride in a. solvent such as pyridine.

6 The following examples are further illustrative of this invention.

' Example 1 Ida-THIOACETOXY-A -PREGNADIENE-3,20-DIONE- 21-OL ACETATE lized by addition of a little ether and recrystallized from acetone-hexane.

RESP 238 mu Example 2 16a-THIOACETOXY-A -PREGNATRIEN E-3,20-DIONE- 21-OL ACETATE Two grams of the product of Example 1 are fermented by means of Corynebacterium simplex (ATCC 6946) according to the procedure of U.S. Patent 2,837,464 of A. Nobile, 6/3/58. The crude product is chromatographed on Florisil and the fractions eluted with 30% ether in hexane are combined and crystallized from acetone-hexane to give the desired product.

Example 3 l6a-THIOACETOXY-2O-CYANO-A -PREGNATRIENE- 20,21-DIOL-3-ONE 2l-ACETATE A solution of. 1.5 g. of the compound of Example 2 in 15 m1. of ethanol and 5 ml. of acetic acid is cooled to 0 C. and treated with 3.5 g. of potassium cyanide. The solution is stirred for 30 minutes, then allowed to warm to room temperature and diluted with water. The product is filtered, washed well with water and recrystallized from ethyl acetate.

Example 4 16a-THIOACETOXY-ZO-CYANO-A -PREGNA- TETRAENE-21-OIr3-ON'E ZLACETATE A solution of 2.0 g. of the compound of Example 3 in 20 ml. of dry pyridine is treated with 2 ml. of phosphorus oxychloride and the mixture allowed to stand at room temperature for 18 hours. It is then poured into ice-water and the product filtered, washed well with water, dissolved in acetone, treated with decolorizing carbon and crystallized from aqueous acetone.

Example 5 16a-THIOACETOXY-A -PREGN ATRIEN E-1'7 a,21-DIOL- 3,20-DIONE 21-ACETATE A solution of 1.0 g. of the compound of Example 4 in 35 ml. of acetone containing 1 ml. of piperidine is chilled to 0 C. and treated with 920 mg. of fine granular potassium permanganate. The reaction mixture is stirred at 0 C. for 1 /2 hours, then warmed to room temperature and a solution of 0.2 ml. of acetic acid in 2 ml. of acetone added dropwise withstirring. After 1 /2 hours, the reaction mixture is diluted with chloroform and treated with bisulfite and l N sulfuric acid todissolve the manganese dioxide. The mixture is extracted with chloroform, and the extracts washed with water and concentrated to ml. The solution is stirred vigorously with 100 ml. of 5% potassium bicarbonate for one hour, then the organic layer is separated, washed with water and evaporated to dryness under reduced pressure. The product is crystallized by addition of a small amount of ether, filtered and recrystallized from pentane-methylene chloride.

Example 6 16a-THIOACETOXY4)a-BROMO-A -PREGNADIENE-32O- DIONE 11B,17a,21-TRIOL ZI-ACETATE A suspension of 500 mg. of the compound of Example 5 in 50 ml. of dioxane and 5 ml. of water, containing 250 mg. of N-bromoacetamide and 2.5 ml. of 1.5 N perchloric acid is stirred for two hours. The resulting solution is treated with 500 mg. of sodium sulfite in 5 ml. of water and the solution extracted with methylene chloride. The extracts are washed with water, dried and the solvent removed under reduced pressure. The residue is crystallized from acetone to give the desired product.

Example 7 16aTHIOACETOXYPREDNISOLONE 21-ACETATE A solution of 100 mg. of the product of Example 6 in 30 mg. of ethanol and 5 ml. of water is shaken with zinc dust at room temperature for 18 hours. At the end of this period the zinc dust is filtered all and washed with ethanol. The alcoholic solution is concentrated in vacuo, water is added, and the aqueous suspension extracted with chloroform. The extract is evaporated to dryness and the residue chromatographed on silica gel. Elution with 1:1 benzene-chloroform yields the compound of Example 5. After some mixed fractions elution with chloroform gives the desired product, which is crystallized from acetone.

Example 8 1Ga-THIOACETOXYPREDNISONE 21-ACETATE A solution of 100 mg. of the compound of Example 7 in ml. of acetone is cooled to 0 C. and titrated with chromic-sulfuric acid reagent (266 mg. chromic acid/ ml.) until persistance of orange color. A few drops of methanol are added to destroy excess reagent, then the solution is diluted with water and the product extracted with methylene chloride. Evaporation of the solvent and crystallization of the residue from acetonehexane gives the desired compound.

Example 9 l6a-THIOACETOXYPREDNISOLONE A solution of 75 mg. of the compound of Example 7 in a mixture of ml. of methanol, 3 ml. of chloroform, 1 ml. of water, and 0.75 ml. of concentrated hydrochloric acid is allowed to stand at room temperature for 48 hours. The solution is diluted with water and extracted with methylene chloride. The extracts are washed with water and the solvent removed in vacuo. The product is crystallized from acetone-hexane.

Example 10 1 6a-THIOACETOXY-9B,11 B-OXIDO-A PREGNADIENE- 17a,21-DIOL3,20-DIONE 2LACETATE To a solution of 300 mg. of the compound of Example 6 in ml. of methanol is added 300 mg. of potassium acetate. The mixture is refluxed for 2 hours, then the solvent is removed under reduced pressure. The residue is triturated with water, filtered, washed with water and crystallized from aqueous acetone to give the desired product.

Example 11 16a-THIOACETOXY-9 a-FLUOROPREDNI SOLONE 21 ACETATE A solution of 250 mg. of the compound of Example 10 in 15 ml. of redistilled chloroform is saturated with anhydrous hydrogen fluoride at 0 C. The mixture is allowed to stand at 0 C. for 5 hours, then the solvent is blown off under a stream of nitrogen; The residue is crystallized from acetone to give the desired product.

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8 Example 12 lfia-THIOACETOXY-Qa-FLUOROPREDNISONE ZI-ACETATE The compound of Example 11 (100 mg.) is oxidized with chromic-sulfuric acid reagent according to Example 8. The product is crystallized from acetone-hexane.

Example 13 1Ga-THIOACETOXY-Qa-FLUOROPREDNISOLONE The compound of Example 11 (100 mg.) is hydrolyzed according to Example 9. The product is crystallized from acetone.

Example 14 1 tie-TH IOACETOXY-ZO-CYANO-A -PREGNADIENE- 20,21-DIOL-8-ONE 21-ACETA'IE A solution of 1.0 g. of the compound of Example 1 in ethanol is treated with 3 g. of potassium cyanide according to Example 3. The reaction is worked up as described and the product crystallized from ethyl acetate.

Example 15 16a-THIOACETOXY-2O-CYANO-A -PREGNATRI- ENE-21-OL-3-ONE 21-ACETA'1E A solution of 1.5 g. of the compound of Example 14 in pyridine is dehydrated and the product purified according to Example 4. The product is crystallized from aqueous acetone.

Example 16 16wTHIOACETOXY-A -PREGNADIENE-17a,21-DIOL- 3,20-DIONE ZI-ACETA'IE One gram of the compound of Example 15 is reacted according to the procedure of Example 5. The product is purified as described and crystallized from hexanemethylene chloride.

Example 17 9a-BROMO-lfia-THIOACETOXYHYDROCORTISONE 21-ACETATE Treatment of 500 mg. of the compound of Example 16 with water and N-bromoacetamide according to the procedure of Example 6, and crystallization of the crude product from acetone gives the desired product.

Example 18 Ilia-THIOACETOXYHYDROCORTISONE ZI-ACETATE A sample of 100 mg. of the product of Example 17 is reduced with zinc according to Example 7. The crude product is purified as described and the desired product crystallized from acetone.

Example 19 lfia-THIOACETOXYCORTISONE 21-ACETATE The product of Example 18 mg.) is oxidized according to Example 8. The product is crystallized from acetone-hexane.

Example 20 1 6a-THIOACETOXYHYDROCORTISONE The compound of Example 18 mg.) is hydrolyzed according to Example 9. The product is crystallized from acetone-hexane.

Example 21 16a-THIOACETOXY-9B,11B-OXIDO-N-PREGNENE-17a,21- DIOL-3,20-DIONE 21-ACETATE A solution of 500 mg. of the compound of Example 17 in methanol is treated with potassium acetate according to Example 10. The product is crystallized from aqueous acetone.

Example 22' 16a-THIOACETOXY-Qa-FIJUOROHYDBOCORTI'SONE 21-ACETATE Treatment of 200 mg. of the compound of Example 21 with hydrogen fluoride according to Example 11 gives the desired material which is crystallized from acetone.

Example 23 1 Ga-THIOAC'ETOXY-Q a FLUOROCORTISONE 21-ACETAT'E The compound of Example 22 (100 mg.) is oxidized with chromic-sulfuric acid reagent according to Example 8. The product is crystallized from acetone-hexane.-

Example 24 16a-THIOACETOXY-9a-FLUOROHYDROCORTISONE The compound of Example 22 (100 mg.) is hydrolyzed according to Example 9. The product is crystallized from acetone.

Example 25 16a-THIIOACEXEOXYPREDNIESCLONE 2l-PROPIONATE A solution of 200 mg. of the compound of Example 9 in ml. of dry pyridine is treated with 0.5 m1. of propionic anhydride and allowed to stand at room temperature for 3 hours. The solution is poured into ice-water and the product filtered and crystallized from acetone-hexane.

Example 26 lfia-THIOACETOXY-Q a-FLUOROPREDNISOLON E ZI-CARBETHOXYLATE A solution of 250 mg. of the compound of Example 13 in 5 ml. of dry pyridine is treated with 0.5 m1. of ethyl chlorocarbonate and allowed to stand at room temperature for 4 hours. The mixture is then poured into icewater and the product filtered and crystallized from acetone.

Example 27 16a-THIOMETHYL-A PREGNADIENE3,20-DI0NE- 21-0L ACETATE To a solution of 50ml. of benzene, 81 ml. ofmethyl mercaptan and 1.5 ml. of piperidine is added 5 g. of A -pregnatriene-3,20-dione-2l-ol acetate. The reaction mixture is stirred atroom temperature for 48 hours. Water is added and'the benzene phase separated, washed 2 times with dilute hydrochloric acid, and then with water again. The organic phase is dried over magnesium sulfate, filtered and'evaporated to'a residue.

Crystallization from acetone-hexane affords the compound of this example.

Example 28 16a-THIOMETHYL-A PREGNATRIENE-3,2O-DIONE- -21-OL ACETATE Two grams of the product of Example 27 are fermented with Corynebacterium simplex (ATCC 6946) according to the procedure of US. Patent 2,837,464 of A. Nobile, 6/ 3/58. The crude product is crystallized from acetonehexane to give 16a-thiomethyl-A -pregnatriene-3,20- dione-Zl-ol acetate.

Example 29 16a-THIOMETHYL-2O-CYANO-N -PREGNATRIENE 20,21-DIOL- 3-ONE 21-ACETATE A solution of 1.5 g. of. the product of Example 28 in 15 ml. of ethanol and 5 ml. of acetic acid is cooled to 0 C. and treated with 4.5 g. of potassium cyanide. The solution is stirred for 30 minutes, then allowed to warm to room temperature and diluted with water. The product is filtered, washed well with water and crystallized from acetone-hexane, thus affording the compound of this example.

Example 30 16aTHIOMZETHYL-20-CYANO-A -PREGNATETRA ENE-21-OL-3-ON E ACETATE According to the procedure of Example 4, 2.0 g. of l6u-thiomethyl-20-cyano-A -pregnatriene-20,21-diol-- 3-one 2l-acetate is treated with 2 ml. of phosphorus oxychloride in pyridine. Crystallization of the crude reaction product from acetone-hexane affords the desired compound;

Example 31 16a-THIO METHYL-A -PREGNATRIENE-l711,21-DIOL- 3,20-DIONE ZI-ACETATE One gram of the compound of Example 30 is treated with 500 mg. of potassium permanganate in a manner similar to Example 5. Crystallization of the crude product from methylene chloride-hexane gives l6a-thiomethyl- A -pregnatriene-17a,2l-diol-3,20-dione 21-acetate Example 32 16a-THIOMETHYL-9 a-BROMO-A --PREGNADIENE-3,2O- DIONE-1lB',17a,21-TRIOL 21-ACETATE Example 33 lfia-THIOMETHYLPREDNISOLONE 21-ACETATE A solution of mg. of the product of Example 32 in 35 ml. of ethanol and 5 ml. of water is shaken with zinc dust at room tempenature for 19 hours. At the end of this time the zinc dust is removed by filtration. The filtrate is evaporated under reduced pressure to approximately 8 ml. Water is added and the aqueous suspension extracted with chloroform. The organic extracts are evaporated to dryness and the residue is treated with acetone-hexane, affording the desired 16a-thiomethylprednisolone 2l-acetate.

Example 34 16a-THIOMETHYLPREDNISONE ZLACETATE A solution of 100 mg. of the compound of Example 33 in 10 ml. of acetone is cooled to 0 C. and allowed to react with 0.056 ml. chromic-sulfuric acid reagent (266' mg. chromium trioxide/ml.). A few drops of methanol are added to destroy any excess reagent, then the solution is diluted with water and the product extracted with methylene chloride. Evaporation of the solvent and crystallization of the residue from acetonehexane affords the compound of this example.

Example 35 ISa-THIOMETHYLPREDNISOLONE A solution of 76 mg. of the compound of Example 33 in a mixture of 15 ml. of methanol, 3 ml. of chloroform, 1 ml. of water and 0.76 ml. of concentrated hydrochloric acid is allowed to stand at room temperature for 47 hours. The solution is diluted with water and extracted with methylene chloride. The extracts are washed with water and the solvent removed under reduced pressure to a residue which upon crystallization from acetonehexane affords the desired compound.

The extracts are washed with water, dried 1 1 Example 36 16a-THIOMETHYL-9B,11B-OXIDO-A PBEGNADIENE- 17 a,21-DIOL-3,20-DION E 21-AC'E1ATE To a solution of 300 mg. of the compound of Example 32 in 20 ml. of methanol is added 300 mg. of potassium a'cetate. The mixture is refluxed for 2 hours, then the solvent is removed under reduced pressure. The residue is triturated with water, filtered, washed with water and crystallized from aqueous acetone to give the desired product.

Example 37 l6a-THIOl\IETHYL-9 a-FLUOROPREDNISOLONE 21-ACETATE A solution of 260 mg. of the compound of Example 36 in 16 ml. of redistilled chloroform is saturated with anhydrous hydrogen fluoride at C. The mixture is allowed to stand at 0 C. for hours, then the solvent is blown ofi? under a stream of nitrogen. The residue thus obtained affords the desired product upon cystallization from acetone.

Example 38 16a-THIOMETHYL-9 a-FLUOROPREDNI SONE ACETATE The compound of Example 37 (100 mg.) is oxidized with chromic-sulfuric acid reagent according to Example 34. Crystallization of the crude product from acetone-hexane affords the compound of this example.

Example 39 1Ga-THIOMETHYL-Qa-FLUOROPREDNISOLONE The compound of Example 37 (100 mg.) is hydrolyzed according to Example 35. The crude product which is isolated is crystallized from acetone-hexane thereby affording the compound of this example.

Example 40 1Ga-THIOMETHYL-ZO-CYANO-M' -PREGNADIENE- 20,21-DIOL-3-ONE 2l-ACETATE A solution of 1.0 g. of the compound of Example 27 in ethanol is treated with 3 g. of potassium cyanide according to Example 29. The reaction is worked up as described and the desired material is obtained after crystallization from ethyl acetate.

Example 41 16a-THIOMETHYL-2O-CYANO-A PREGNATRIENE- 21-OL-3-ONE ZVI-VACETATE A solution of 1.6 g. of the compound of Example 40 in pyridine is dehydrated according to Example 4 with phosphorous oxychloride. Crystallization of the reaction product from acetone-hexane affords the compound of this example.

Example 42 l6a-THIOMETHYL-M -PREGNADIENE-17a,21-DIOL- 8,20-DIONE 21-ACETATE One gram of the compound of Example 41 is reacted with potassium permanganate according to Example 31. The reaction is worked up in a manner similar to the procedure described in Example 5. Crystallization from methylene chloride-hexane aifords the desired compound.

Example 43 16a-THIOMETHYL-Qa-BROMOHYDROCORTISONE 21-ACETATE Treatment of 500 mg. of the compound of Example 42 with N-bromoacetamide and water according to the procedure of Example 32 affords after crystallization from acetone-hexane the desired product.

12 Example 44 1da-THIOMETHYLHYDROCORTISONE ZI-ACETATE A sample of mg. of the product of Example 43 is treated with zinc according to Example 7. Work-up of the reaction solution in a manner similar to that described in Example 30 affords the desired product.

Example 45 1fia-THTOMETHYLCORTISONE 2l-ACETATE The product of Example 44 (100 mg.) is oxidized according to Example 34. Work-up in the manner described affords the product of this example.

Example 46 1Ga-THlOItiETHYLHYDROCORTISONE The compound of Example 44 (75 mg.) is hydrolyzed according to Example 35. The product is crystallized from acetone-hexane.

Example 47 lfia-THIOMETHYL-9fl,IIB-OXIDO-N-PREGNENE-l70.,21- DIOL-3,20-DIONE 21-ACETATE A solution of 300 mg. of the compound of Example 43 in methanol is treated with potassium acetate according to Example 36. The product is crystallized from aqueous acetone.

Example 48 1Ga-THIOMETHYL-Qa-FLUOROHYDROCORTISONE 21-ACETATE A solution of 260 mg. of the compound of Example 47 in 16 ml. of redistilled chloroform is saturated with hydrogen fluoride according to Example 37. The reaction mixture is treated according to the latter example, whereby one obtains the desired product upon crystallization from acetone.

Example 49 lfia-THIOMETHYL-Q a-FLUOROCORTISONE 21-ACETATE The compound of Example 48 (100 mg.) is oxidized with chromic-sulfuric acid reagent according to Example 34. The product is crystallized from acetone-hexane.

Example 5 0 1 Sa-THIOMETHYLQa-FLUOROHYDROCORTISONE The compound of Example 48 (100 mg.) is hydrolyzed ac'cording to Example 35. The product is crystallized from acetone.

Example 51 IGa-THIOMETHYLPREDNISOLONE 21-PROPIONATE A solution of 200 mg. of the compound of Example 35 in 6 ml. of dry pyridine is treated with 0.6 ml. of propionic anhydride and then allowed to stand at room temperature for 4 hours. The solution is poured into ice-water and the product filtered and crystalilzed from acetone-hexane.

Example 52 We claim:

1. A compound selected from the group consisting of 16a-thiol steroids of the formula and the 1(2)-dehydro analogues thereof wherein R is a substituent selected from the group consisting of H, lower alkyl, and lower alkanoyl; R is a substituent selected from the group consisting of H, monoand dicarboxylic acid radicals having up to carbon atoms, the sulfate radical, and the phosphate radical; Y is a substituent selected from the group consisting of (I-LflOH) and =0; and X is a substituent selected from the group consisting of H and halogen.

2. The chemical compound l6a-thioacctoxyprcdniso lone 21-acetate.

3. The chemical compound 16a-thioacetoxyprednisone ill-acetate.

4. The chemical compound l6a-thioacetoxyprednisolone.

5. The chemical compound 16u-thioacetoxy-9a-fluoroprednisolone 2l-acetate.

6. The chemical compound 16a-thioacetoxy-9u-fluoroprednisone 21-acetate.

7. The chemical compound 16a-thioacetoxy-9tt fluoroprednisolone.

8. The chemical compound 16a-thiomethylprednisolone ZI-acetate.

9. The chemical compound 16a-thiomethylprednisone ZI-acetate.

10. The chemical compound l6a-thiomethylprednisolone.

11. The chemical compound 16a-thiomethyl-9a-fluoroprednisolone 21-acetate.

12. The chemical compound 16a-thiomethyl-9a-fluoroprednisone 21-acetate.

13. The chemical compound 16u-thi0methyl-9a-fiuoroprednisolone.

14. The chemical compound 16a-thioacetoxypredniso lone 21-propionate.

15. The chemical compound l6a-thi oacetoXy-9afluoroprednisolone ZI-carbethoxylate.

16. The chemical compound la-thiomethylpredisolone 2l-propionate.

17. The chemical compound l6a-thiomethyl-9a-fiuoroprednisol one ZI-carbethoxylate.

References Cited in the file of this patent UNITED STATES PATENTS 2,773,080 Bernstein et al. Dec. 4, 1956 2,777,864 Bernstein et a1 I an. 15, 1957 2,789,118 Bernstein et al Apr. 16, 1957 2,806,043 Bernstein et a1 Sept. 10, 1957 2,814,632 Nussbaum Nov. 26, 1957 2,831,003 Thomas Apr. 15, 1958 2,912,443 Dodson et al Nov. 10, 1959 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 16A-THIOL STEROIDS OF THE FORMULA 